The present invention generally relates to high power waveguide systems, and more particularly to waveguide systems for delivering microwave pulse power to a load. The invention is directed to a waveguide system for controlling the pulse power output of microwave generators, especially self excited oscillators. The invention can be advantageously used with magnetrons, which only behave reasonably well over a limited power level range.
A magnetron produces an output of short pulses of high power microwave energy as a result of very short pulses of applied voltage. For some applications, it is desirable to deliver pulse power to a load, wherein the power magnitude for consecutive pulses varies from one pulse to the next, such as alternating between a pulse at full peak power to a pulse of attenuated power, e.g. one-half power (or less). Heretofore, it generally has not been practical to use magnetrons in such applications. The problem with using magnetrons in such applications is that magnetrons do not behave well when their applied voltage is varied from pulse to pulse.
The present invention provides a new microwave pulse power switching system (sometimes referred to herein as a “switcher” or “waveguide switcher”) that permits self-excited oscillators, such as magnetrons, to be used in applications where it is desired to deliver to a load high power microwave pulses that differ in magnitudes from one pulse to the next. The invention overcomes the inherent limitations of such self-excited oscillators, which prevent them from being used in such applications.